the wildebeest migration sees almost two million of the animals migrate at the end of the late autumn raining season from the serengeti national park in tanzania to the greener pastures of the maasai mara national reserve in kenya. but first, the wildebeest must cross mara river, where crocodiles await.

more wildebeest, however, will die from being trampled by other wildebeest in the river than from a crocodile. the wildebeest are well aware of the danger, and wait on the bank until the pressure from the back eventually forces those in the front to cross. once the first are in the water, the rest suddenly follow in an almost unstoppable wave.